In cases where gas bubbles generated in or mixed with treated liquids have harmful effect, e.g., in industries using biological organisms, and in water-cleaning plants, papermaking plants and alcohol intermediate manufacturing processes, etc. defoaming agents have conventionally been added to said treated liquids in order to eliminate or decrease the quantity of said gas bubbles.
When conventional techniques using defoaming agents are employed as described above, running costs are high.
Furthermore, the addition of defoaming agents generally diminishes the detergent effect of surfactants, and causes reactions other than those intended. This is especially true in the case of bioreactors and alcohol intermediate manufacturing processes, etc. In such cases, therefore, the treatment process may become difficult or complicated when defoaming agents are added. Furthermore, the effect of the treatment performed in such a treatment processess is often diminished.